This invention relates generally to retractable knife handles adaptable for mounting a replaceable blade. More particularly, this invention relates to a knife handle for a utility knife employing blade which may be slidably moved from a sheathed position wherein the blade is enclosed within the handle to an extended unsheathed position wherein the knife blade projects through an opening in the handle to present a cutting edge.
An exemplary type of knife handle to which the present invention is particularly related is diclosed in U.S. Pat. No. 3,107,426 issued to W. H. Robinson, Jr. on Oct. 22, 1963 and entitled "Utility Knife." Such a utility knife incorporates a blade carrier which mounts and supports the blade at the interior of the handle for longitudinal movement therein. The blade carrier incorporates a thumb actuated button that can be depressed to unlatch the blade from one of several latched positions for shifting the blade via the blade carrier to another longitudinal position. The thumb actuated button extends through a slot in the top of the knife handle and is secured to the blade carrier by means of a resilient finger. The knife handle is further adapted so that the blade may be relatively easily dismounted and replaced. Such knives have found great popularity and are of a great utility in a wide variety of cutting operations.
While the foregoing utility knives are relatively inexpensive to manufacture and generally operate in an efficient and safe manner, a common problem of such retractable knives is a loose or rattling blade condition. The mounted blades often tend to exhibit side wobble characteristics when the blades are advanced to the extended unsheathed position--especially when the blade is subjected to cutting stresses. The looseness or side wobble of the blade frequently detracts from the many positive characteristics of retractable utility knives. The present invention is specifically directed to eliminating the loosenes and side wobble in retractable utility knives.